A strategy to synthesis amine-functional Poly(Divinylbenzene)HIPEs with controllable porous structure for effective CO2 adsorption

Abstract

A novel PolyHIPEs with hierarchically porous structures was prepared by the polymerization of divinylbenzene via high internal phase emulsions (HIPEs) template method. The proper pore-forming agents and post-crosslinking strategy were used to create and tailor the meso- and micro-porous structure on Poly(Divinylbenzene)HIPEs. Pentaethylenehexamine (PEHA) was introduced in PolyHIPEs to prepare solid amine adsorbents for CO2 capture. The increase of specific surface area from 81.80 to 1003.02 m2/g indicated the successful porous structure design of PolyHIPEs. Dynamic CO2 adsorption experiment results proved that the Micro-PDVB-0.3PEHA and H-PDVB-0.3PEHA didn’t show satisfactory CO2 adsorption performance, though the two supports had remarkably higher specific surface area. They showed lower CO2 adsorption capacities of 0.78 and 1.36 mmol/g respectively at 40 ℃ than that of C-PDVB-0.3PEHA (2.73 mmol/g) and Meso-PDVB-0.3PEHA (3.66 mmol/g) with mesoporous structure. The results of CO2-TPD experiment and kinetics investigation verified that the loading amine compounds would preferentially fill into and block the micropores, which would hinder CO2 molecules to diffuse into the inner part of the filling amine in turn, thus reduce the amine utilization efficiency. Meso-PDVB-0.4PEHA from Meso-PDVB with abundant mesopores, exhibited the highest CO2 adsorption capacity of 4.52 and 4.99 mmol/g with N efficiency of 0.61 and 0.67 under dry and wet condition, respectively. The excellent regeneration performance of Meso-PDVB-0.4PEHA, combined with its superior CO2 adsorption capacity and ultra-high N efficiency, makes it a promising adsorbent for CO2 capture from flue gas.